Also graphite is better than steel because dirt don’t stick to it so it is less of a hassle. Buy on ebay dirt cheap.

a good link to what is needed to know is:
http://www.metaldetectingworld.com/electrolysis_rust_removal.shtml

I filled the thing with old nuts, bolts and washers and maybe 1/2 gal of water, and shook for 15 min. It’s heavy and I’m a girl and it sucked, but then I filled it with 3 gallons of regular white vinegar and let it sit for four days. I drained, strained, and saved the vinegar. I shook it with water and nuts and bolts again for 15 minutes (maybe really only 10) and rinsed it a bunch, and then refilled with the filtered vinegar and let it sit for another three or four days.

By the weekend I drained it out and was pretty thrilled to find it damn clean. Still some rusty spots, but it was like 93% shiny. I did rinse it with water from the garden hose a bunch and then sat the tank on my apartment’s heater for a few days to thoroughly dry out.

It was a free tank, so was kind of an experiment. Also note, I removed the paint on the outside, so can’t speak for what the vinegar will do to paint. It created some light streaks on the bare steel. I used enough aircraft stripper on that job to destroy my carbon footprint for a while.. thought I’d try organic on the inside.

I expected some flash rust, but it seems to be okay. I expected the outside to rust quickly too, but sprayed it with Gibbs and rubbed down. I may end up needing to treat the inside, but am focusing on jetting issues and the rest of this bike’s rebuild for now.

An advantage of using washing soda instead of salt is that yuou can dump the solution in the garden when you are done, it won’t harm anything.

One more caution.. this process works for the inside of gas tanks, and ordinary iron or steel parts in a solution bath. it does not work well for stainless steel. And DO NOT use it for chromed parts, unless you like handling carcinogenic chromates in the used solution (which are classed as toxic, hazardous waste).

Instead of muriatic acid, I plan to use phosphoric acid to wash out the tank. Phosphoric acid will react with any remaining rust in the tank to form iron phosphate, which forms a neutral, passive layer that protects the underlying metal from further rust.

I scraped a little bit of paint off of the tank lip that fits into the rubber mount just infront of the seat and attached the positive there.

The positive should be attached to the tank and the negative to the rod because electricity flows from positive to negative and I would think that’d be the logical way you would want the current flowing…